Tagged With "spot"

Topic

Heavy Spot and High spot after 1 critical Speed

! ! Shabir Ahmad KHAN® ·
What happens to Heavy Spot after first critical speed and 180 phase shift. Is Heavy Spot lead or lag high spot. Or anything else.
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Re: Heavy Spot and High spot after 1 critical Speed

Jason Tranter ·
This is a pretty major topic; here is a summary. The heavy spot is the physical unbalance (the sum of all the unbalance into one vector of angle and mass). The heavy spot does not move. The high spot is the peak of the waveform detected as a result of the heavy spot. Well below critical, the high spot is in phase with the heavy spot. For simplicity's sake, there is no lag. Above critical, theoretically, the high spot is opposite the heavy spot. It is a long discussion about exactly how much...
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Re: Heavy Spot and High spot after 1 critical Speed

William_C._Foiles ·
Often, high spot and heavy spot are oversimplified. Imbalance is distributed, especially in a rotor system with multiple natural frequencies. Similarly, there are multiple measurement points - or points that have a measurement, whether measured or not. Mode shape is under appreciated when it comes to the high spot heave spot relation. The location of the measurement compared to the force in a simple case of only one imbalance is important. If using this information for balancing -- and it...
Topic

light spot AND ELECTRONIC PHASE LAG

nishanthreddy33 ·
Dear all, As i am preparing cat-2 kindly please explain me about light spot and electronic phase lag. Thanks in advance,
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Re: light spot AND ELECTRONIC PHASE LAG

John from PA ·
Seems reasonable, after all the VI has an expectation of field balancing both single and two plane for level II.
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Re: light spot AND ELECTRONIC PHASE LAG

Walt Strong ·
You guys are thinking unbalance weight location. Perhaps the OP question is about where the photo-tach or strobe light shines? Walt
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Re: light spot AND ELECTRONIC PHASE LAG

William_C._Foiles ·
More in days gone by did people worry about electronic lag and where the heavy spot were. Light spot in terms of light would be new.
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Re: light spot AND ELECTRONIC PHASE LAG

William_C._Foiles ·
John, Bently asked me this question one time. Nay, Don Bently berated me over light spot. The light spot is opposite the heavy spot.
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Re: light spot AND ELECTRONIC PHASE LAG

Walt Strong ·
Are they (VI and others) now teaching about "light spot" and "electronic phase lag" for CAT-2? Walt
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Re: light spot AND ELECTRONIC PHASE LAG

Walt Strong ·
John, thanks for clearing that up, so now you can explain it to the OP. Walt
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Re: light spot AND ELECTRONIC PHASE LAG

John from PA ·
Clarify, do you really mean "light spot"?
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Re: light spot AND ELECTRONIC PHASE LAG

John from PA ·
LOL. Don, tried to get me once when he asked explain the difference between dampening and damping.
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Re: light spot AND ELECTRONIC PHASE LAG

nishanthreddy33 ·
higspot is max vibration and heavyspot is mass unbalance in between these two topics from where light spot will come.as per theory max vibration opposite is heavyspot with 180 phase shift. kindly please explan me about this i am in confusion
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Re: light spot AND ELECTRONIC PHASE LAG

John from PA ·
Interesting approach...you hijack a thread started by NISHANTHREDDY33, then ask me to do extra work ("...you can find it by searching") to provide you with some help on something totally unrelated to the initial topic. What you ask me to comment on was started by HISHAM4EVER, unless there is something else concerning a "GT SGT600 PT"? If that is what you are asking about, I have very little experience with Siemens turbines, and from what I've read about the problem it seems to be machine ...
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Re: light spot AND ELECTRONIC PHASE LAG

aziz58 ·
dear jhon pls give me your idea about my post that you can find it by searching Unexpected high vibration sgt 600gas turbine thanks in advance
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Re: light spot AND ELECTRONIC PHASE LAG

Walt Strong ·
My Response is Here: https://www.maintenance.org/to...and-4-high-vibration
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